Storage installation

ABSTRACT

938,520. Storing liquefied gases. CONTINENTAL OIL CO. March 7, 1962 [March 20, 1961], No. 8818/62. Class 8(2). [Also in Group XXIX] A reservoir for low temperature liquid gas comprises a container 21 suspended within a depression 17 in the ground above its bottom press means 16 which extend between supports 11 secured on at least two sides of the depression. The container 21 is attached to the crossextending I beams 16 by cables or rods with spring hangers 20 which may be omitted at positions near the centre of the tank which are not greatly affected by expansion. The depression 17 is lined with asphalt, plastic or other impervious material and the space 22 between it and the container 21 is filled with insulating material, loose or in bags. A cover 24 of sheet metal, plastic or other material extends over the beams 16 and its edges dip into a peripheral trough 13 which forms a water-seal. The gas mentioned is meltrane.

July 9, 1963 c. E. SCHROEDER STORAGE INSTALLATION Filed March 20 linkATTORNEY United States Patent 3,096,902 STORAGE INSTALLATION Carl E.Schroeder, Ponca City, Okla, assignor to Continental Oil Company, PoneaCity, Okla., a corporation of Delaware Filed Mar. 20, 1961, Ser. No.96,813 12 Claims. c1. 220 1s This invention relates generally to astorage installation and more particularly to a suspended undergroundstorage tank which may be utilized to contain low temperature liquids.

In large scale refinery and other manufacturing operations it is oftennecessary to store large quantities of liquids either temporarily or forextended periods of time. Heretofore, relatively large above-groundtanks have been utilized for this purpose. However, such tanks have notbeen found to be satisfactory for all conditions which may beencountered; and consequently, improvements in storage facilities havelong been sought. In the usual above-ground storage installation it isoften necessary to do extensive earth work to prepare the ground priorto the erection of the storage tanks. Moreover, relatively elaboratefundations are necessary, as are extensive dikes which must encompass asubstantially greater area than is covered by the tank itself. Incertain areas of extremely hard, irregular soil, the normal problemsattendant to preparation of the area for the storage tanks are greatlymagnified and in some instances may jeopardize the economic feasibilityof the whole project.

With the advent of the use of large quantities of low temperatureliquids, the problems arising from aboveground installation haveincreased. Due to the nature of these liquids, it is necessary that heatloss be maintained at a minimum; and in order to minimize this loss inthe surface storage installations, various schemes have been tried.Among these are the securing of insulating ma terials around theexterior of the tanks and the use of double-walled tanks. In eithercase, the problems attendant to the erection and maintenance of the heatbarriers have proved to be formidable.

The present invention contemplates a novel storage installation whichcan be erected quickly and economically and which is not subject to manyof the problems brought about by surface storage. This installationcomprises one or more foundation members disposed along sides of adepression in the earth. Disposed between each pair of foundationmembers is a support means to which flexible suspension means areconnected in a position substantially over the depression. Secured tothe suspension means is a container into which a material can be placed.Outside the container and within the walls of the depression is provideda vapor barrier as well as a quantity of insulating material.

An important object of this invention is to facilitate the storage ofmaterials with minimum heat loss therefrom.

Another object of this invention is to provide a liquid storageinstallation which does not necessitate the use of extensive dikes.

A further object of this invention is to provide a storage installationwhich may be quickly and economically installed under adverse terrainconditions.

Another object of this invention is to provide a storage installationwherein thermal stresses are minimized.

Yet another object of this invention is to provide a storageinstallation which is less susceptible to puncture or other injury.

Other objects and advantages of the invention will be evident from thefollowing detailed description when read in conjunction with theaccompanying drawings which illustrate one embodiment of my invention.

In the drawings:

FIGURE 1 is a perspective view, partially cut away, of an undergroundstorage installation embodying this invention. Insulation used thereinhas been omitted for clarity.

FIGURE 2 is an enlarged cross sectional view taken on line 22 of FIGURE1 showing in greater detail a vapor sealing arrangement as well asinsulation used therein.

Referring now to the drawings and in particular to FIGURE 1, there isshown along the surface of the earth a plurality of paired foundationmembers 11 which can be partially buried, as indicated at 12 in FIGURE2. While the foundation members are shown in the drawing as being of aparticular shape, it is to be understood that other forms may be used.For example, piling might be substituted for the disclosed structure, ora single pair of substantial parallel horizontal foundations might beused in the place of the plurality of pairs shown. Formed within thebody of each of the foundation members 11 is a U-shaped notch 13 inwhich is shown a continuous elongate trough 14 which can be made ofsteel, plastic, or other impervious materials. As best shown in FIGURE1, liquid, such as water, is placed in trough '14 for a purposehereinafter described. Terminating in proximity to trough 14 are aplurality of support means such as I-beams 16 which are placed on orsecured to the pairs of opposed foundation members 11. The centralportion of each of the beams is suspended over a pit or depression 17formed in the earth and has attached thereto a plurality of clevises 15.To these clevises are attached spring hangers 20 from which dependsuspension means 18 which can be either flexible cable or rigid bar. Itis to be understood that while these suspension means are shown to be ofequal length in the drawings, it is contemplated that they can be ofunequal length, depending upon the relative elevation of foundationmembers 11. Further, the spring hangers 20 may be omitted near thecenter of the tank if desired, or may be omitted entirely when thelength of the installation is such that thermal contraction isrelatively small.

A clevis 19 is attached at the lower end of each of the suspension means18 and has secured thereto a container 21 which is suspended therebyabove the bottom of pit 17. While a reactangular tank having a. squarecross section is shown in the drawings, many other types of tanks may beusedfor this purpose, such as a cylindrical tank, or should the occasionwarrant, a semicircular tank, to mention a few. Moreover, bracing orother stiffening members may be added to the tank as the circumstancesdemand. Such bracing has been omitted in the drawings for clarity, andinasmuch as particular bracing or stiffening arrangements will varydepending upon the size, shape and material of the tank and can be addedby anyone skilled in the art. In addition, if it is desired, cribbingmay be added beneath the tank without departing from. the spirit of thisinvention.

Exterior of container 21 is provided a quantity .of in sulating material22 which may be made of perlite, either loose or in bags, mineral wool,glass Wool or any other insulating materials which are well known andwhich will be obvious to one skilled in the art. Contacting theinsulating material can be a liquid-vapor barrier 23 which is applied tothe sides of pit or depression 17. The barrier may be formed from one ormore of many wellknown materials such as asphalt, gunite, plastic, or avariety of other materials which are well known in the art. Securedabove pit 17 and resting upon I-beams 16, is a substantially impervioussheet or cover 24 having flanges 26 formed on all four edges thereof.This cover can be made of any impervious material such as steel,aluminum or other sheet metal, plastic, rubberized canvas or othermaterials. Flanges 26 extend into the liquid to store only 60,750 cubicfeet.

contained in trough 14 which is disposed on all four sides of pit 17. Bythis arrangement, is it possible to maintain a vapor-tight sealcompletely surrounding pit 17 and thus prevent vapor losses fromcontainer 21. Of course, other edge sealing methods may be utilizedwithout departing from the scope of this invention. For instance, theflanges 26 could be fastened to foundation members 11 with the portionof the flanges between the members being buried. Alternately, a membercould be provided between members 11 to which the flanges 26 could befastened.

In use, a quantity of material, for instance, low temperature LPG isplaced in container 21, after which cover 24 is placed thereon withflanges 26 extending into trough 14. Under these conditions, heat losswill, due to the presence of insulating materials 22, be maintained at aminimum, as will vapor losses due to the sealing arrangement madepossible by flanges 26 and trough 14. Should rupture of the container 21occur, the lack of extensive diking will not be a factor inasmuch as theliquid within the container will flow into pit or depression 17 withoutattendant loss or adulteration of the surrounding countryside. Sinceexte-nsive dike work is not necessary, it is possible by thisarrangement to better utilize a given surface area. Simple computationsindicate that it is possible when using the present installation tostore 486,000 cubic feet of material; where before, using conventionalsurface storage, it was possible Moreover, inasmuch as container 21 issuspended, any thermal expansion or contraction therein will result onlyin the slight lowering or elevating of the bottom of container 21 andslight 1 movement of the ends of container-21 which is allowed byclevises 15 and 19 and will not induce thermal stress therein. 1

While particular embodiments of the invention have been described, itwill be understood, of course, that the invention is not limitedthereto, since many modifications may be made; and it is thereforecontemplated to cover by the appended claims any such modifications asfall within the true spirit and scope of the invention.

The invention having thus been described, what is claimed and desired tobe secured by Letters Patent is:

1. A reservoir comprising a depression in the ground, support meanssecured on at least two sides of said depression and extendingthereacross, a plurality of cables connected 'to said support means anda container secured to said cables and suspended thereby within saiddepression above the bottom thereof.

2. A reservoir comprising a depression in the ground, a plurality ofbeams secured on opposite sides of said depression and extendingthereacross elongate, suspension means depending from each of said beamstoward the bottom of said depression, a clevis at the lower end of saidmeans, and a container secured to said suspension means by said clevisesand suspended thereby Within said depression above the bottom thereof.

v3:. A reservoir comprising a pit in the ground, a plurality of beamssecured on opposite sides of said pit and extending thereacross, aplurality of elongated downwardly extending suspension members securedto each of said beams at the central portion thereof a. clevis at eachend of said members, and a container secured to said suspension membersby said olevises and suspended thereby within said pit above the bottomthereof.

4. A reservoir comprising a pit in the ground, support means secured onat least two sides of said pit and extending thereacross, suspensionmeans connected to said support means, a container secured to saidsuspension means and suspended thereby within said pit above the bottomthereof, a substantially impervious sheet disposed above said container,and means for sealing the edges of said sheet to prevent escape of vaporfrom said pit.

5. A reservoir comprising a pit formed in the ground, a plurality ofbeams secured on opposite sides of said pit and extending thereacross, aplurality of elongated, downwardly extending suspension members securedto each of said beams on the central portion thereof, a containersecured to said suspension members and suspended thereby within said pitabove the bottom thereof, a substantially impervious sheet disposedabove said beams, and means for sealing the edges of said sheet toprevent escape of vapor from said pit.

6. A reservoir comprising a depression in the ground, support meanssecured on at least two sides of said depression and extendingthereacross, suspension mean connected to said support means saidsuspension means including a clevis at the points of connection withsaid support means and a spring secured to each clevis, a containersecured to said suspension means, a liquid barrier between saidcontainer and the walls of said depression, and insulating materialdisposed between said barrier and said container.

7. The structure recited in claim 6 wherein said support means include aplurality of beams.

8. The structure recited in claim 7 wherein said suspension meansincludes a cable connected to each of said springs.

9. The structure recited in claim 8 wherein a substantially impervioussheet is disposed above said support means and means are provided forsealing the edges of said sheet to'prevent escape of vapor from saiddepression.

10. The stnucture recited in claim 6 wherein a plurality of foundationmembers are provided beneath a portion of said support means.

11. The structure recited in claim 10 wherein a substantially impervioussheet is disposed above said support means.

12. A reservoir comprising a depression in the ground, a plurality ofbeams secured on at least two sides of said depression and extendingthereacross, a plurality of cables connected to said beams, a containersecured to said oables, a liquid barrier between said container and thewalls of said depression, insulating material disposed between saidbarrier and said container, a substantially impervious sheet disposedabove said support means, and means for sealing the edges of said sheetto prevent the escape of vapor from said depression.

References Cited in the file of this patent UNITED STATES PATENTS

1. A RESERVOIR COMPRISING A DEPRESSION IN THE GROUND, SUPPORT MEANSSECURED ON AT LEAST TWO SIDES OF SAID DEPRESSION AND EXTENDINGTHEREACROSS, A PLURALITY OF CABLES CONNECTED TO SAID SUPPORT MEANS AND ACONTAINER SECURED